FIG. 1 illustrates a network architecture for Proximity Services (ProSe). As shown in FIG. 1, ProSe refers to a service that supports a data transfer path enabling two user equipments (UEs) to directly exchange data without use of the infrastructure of a mobile communication network. In other words, ProSe enables proximate UEs to exchange data through a direct data path without help of the backhaul of a mobile communication network.
To implement a ProSe application utilizing a direct data path as shown in FIG. 1, it is necessary to discover a device to communicate and identify the need for communication with the device. For example, when a user wishes to take a proximate taxi for Seoul by use of a ProSe based taxi finding application, it is necessary to find or identify a device or UE running the taxi finding application with interest information “not taken by a passenger and can go to Seoul”.
In addition, it is necessary for UEs being allowed to run specific applications to exchange messages.